This invention relates to heavy duty V-type drive belts commonly used in agricultural and variable speed applications including automotive traction applications. Such belts can find use in continuously variable transmissions for automobiles and in agricultural traction drives such as in a combine where high horsepower loads are being transferred from the power plant to the drive train. Because of the rigorous environment in which such belts operate and the extremely high tensile loads placed on the belt, such belts are generally made thicker, having a lower ratio of top width to belt thickness than V-type belts used for light duty applications. These heavy duty V-belts must exhibit considerable transverse rigidity in order to maintain the primary tensile members in an planar orientation to facilitate uniform load bearing across the width of the belt while the belt is under tension. The portion of a heavy duty V-belt which is subjected to substantial tensile stress is conventionally known as the tension section and the portion of the belt construction subjected to compressive stresses is known as the compression section. The belt bends or flexes about a neutral axis section which is located between the tension and compression section and is primarily composed of longitudinally oriented, substantially inextensible tightly twisted tensile bearing cords. In general, the tensile load put upon the belt is known to be directly proportional to the tendency of the tensile members to be distorted out of a substantially horizontal plane. The load bearing capability of a particular V-belt construction is primarily dependent on the degree of support which the compression section of the belt can supply to the tensile bearing members in the construction. Therefore, transverse stiffness is of primary importance in maximizing the power which can be conveyed by a heavy duty drive belt.